Futures Gap Trading

Markets are not perfectly efficient, especially across the lower-liquidity overnight session. Gaps occur because: 1) US index futures trade nearly 24 hours, but the regular cash session (9:30 AM-4:00 PM ET) carries most of the volume, so an open 'gap' still forms versus the prior cash close, 2) news and events happen overnight, shifting sentiment while RTH liquidity is thin, 3) the overnight Globex session and global futures provide price discovery, 4) opening orders and the opening auction create imbalances at the 9:30 ET open. Gaps represent the market's adjustment to overnight information - a feature of concentrated regular-session liquidity, not a market failure.

No. Be selective: 1) Trade gaps meeting minimum size threshold (< 0.1% gaps are noise). 2) Skip gaps on news-heavy days until you're experienced with event gaps. 3) Prefer common gaps for filling, which are easier to identify. 4) Skip Monday morning gaps initially (weekend creates uncertainty). 5) Start with 2-3 gap trades per week, focusing on highest-probability setups. Quality over quantity.

This is normal risk in gap trading. Protection: 1) Your stop is beyond gap extreme + buffer, so you have defined max loss. 2) Don't add to losing position hoping for reversal. 3) If stopped out, don't immediately re-enter same direction - the gap may be breakaway type. 4) Accept that some gaps don't fill the same day. Your stop protects against catastrophic loss while allowing the thesis time to work.

Most gaps (70-80%) fill eventually, but 'eventually' can mean days, weeks, or months. Breakaway gaps starting major trends may never fill. For intraday gap trading, focus on same-day fills of common gaps. Don't hold positions for days expecting old gaps to fill. Each day is a fresh trade - if gap doesn't fill today, reassess tomorrow. Some professional systems track multi-day gap fill, but this requires different capital management.

Quick identification framework: 1) Was there a major overnight news/event? If yes, likely breakaway or continuation, not common. 2) Is gap within previous day's range? If yes, likely common gap (fill). 3) Is gap beyond key support/resistance? If yes, potential breakaway. 4) Check volume first 5-10 minutes: high volume = conviction behind gap; low volume = common gap. 5) When uncertain, wait and observe - gap behavior in first 15-30 minutes clarifies type.

VIX significantly impacts gap behavior: 1) Low VIX (< 14): more predictable market, gaps fill more reliably (75%+ fill rate). 2) Normal VIX (14-18): standard fill rates (~70%). 3) High VIX (> 18): erratic behavior, gaps may extend further or whipsaw, lower fill rate (55-60%). 4) VIX spike: gap behavior unreliable, consider skipping gap trades. Track your gap fill rates by VIX regime and adjust strategy accordingly.

Statistical analysis shows: 1) Monday: lower fill rates (~65-68%) due to weekend news accumulation and uncertainty. 2) Tuesday-Thursday: highest fill rates (~75-80%), most predictable. 3) Friday: moderate fill rates (~70%), traders may be positioning for weekend. 4) Expiry days: erratic behavior, avoid gap trading. Start by focusing on Tuesday-Thursday gaps. Add Monday/Friday after gaining experience.

Previous day's range provides key reference points: 1) Gap opens at previous high (gap up) or low (gap down): strong support/resistance nearby, good fade entry level. 2) Gap opens beyond previous range: potential breakaway, don't fade blindly. 3) Gap into mid-range: typical common gap, moderate fade opportunity. 4) Calculate gap size relative to previous range: gap > 50% of previous range = significant move. Use previous high/low as natural support/resistance for stop placement.

Partial fill approach when: 1) Gap is medium-sized (0.3-0.7%) - may not fully fill same day. 2) Time approaching midday with incomplete fill. 3) Price approaching support/resistance within gap zone. 4) Your P&L is positive but momentum stalling. Full fill approach when: 1) Small gap (< 0.3%) - high probability of full fill. 2) Strong rejection from gap extreme with momentum toward fill. 3) Gap is clearly common type with no catalyst. Default to partial fill strategy for consistency.

Key differences: 1) Single-stock gaps can be larger and more name-specific (earnings, news). 2) Single names can have lower liquidity than the index futures - wider spreads at open, more slippage. 3) Stock gap fills can take longer (less arbitrage pressure). 4) Index gaps reflect broad sentiment; single-stock gaps can be idiosyncratic. Approach: prefer index futures (ES, NQ) for gap trading due to liquidity. For single names, only trade large-cap, highly liquid stocks or ETFs (e.g., SPY, QQQ, AAPL). Require a larger gap-size threshold for single names. Be more patient with fill time.

Model components: 1) Dependent variable: binary (filled/not filled) or time-to-fill. 2) Independent variables: gap size percentile, gap vs previous range, VIX level, day of week, overnight Globex volume, previous day's trend, distance from key levels. 3) Method: logistic regression for probability, survival analysis for time-to-fill. 4) Training: minimum 500 gaps over 3-5 years. 5) Validation: out-of-sample testing, walk-forward analysis. 6) Output: probability score (e.g., 75% fill probability) informing position size and confidence. Update model quarterly with new data.

Strategy by scenario: 1) High-probability fill (common gap, low VIX): sell OTM options in gap direction - short calls for gap up fill, short puts for gap down fill. Theta decay helps. 2) Breakaway gap continuation: buy ATM options in gap direction for leveraged directional exposure with defined risk. 3) Uncertain gap resolution: buy straddle/strangle - profits from large move either direction. 4) Gap fill with hedged exposure: buy put (gap up) or call (gap down) as insurance while fading with futures. Consider IV level - options often expensive at volatile opens.

Framework: 1) Overnight Globex move: if ES/NQ move strongly overnight, the regular-session open gaps accordingly. 2) Asian/European sessions: moves in Japanese, Hong Kong, and European markets overnight shape the US open. 3) Rates/currency: a sharp move in Treasury yields or the dollar (often around data releases) can drive index gaps. 4) Commodity gaps: a crude oil move can affect energy names and overall sentiment. Strategy: build a dashboard tracking overnight moves across correlated markets. Strong multi-market alignment increases gap-continuation probability; divergence (the US gapping against global direction) increases fill probability.

Integration approach: 1) Allocation: gap trading typically 10-20% of systematic portfolio. 2) Correlation: gap trades are short-term, lower correlation with multi-day strategies - good diversification. 3) Risk budget: daily gap risk allocation (e.g., max 2% capital at risk in gap trades). 4) Performance attribution: track gap P&L separately from other strategies. 5) Regime adaptation: reduce gap allocation in high VIX or trending markets where fills are less reliable. 6) Edge monitoring: track fill rates monthly; if degrading, reduce allocation or pause.

Warning signs: 1) Fill rate declining consistently (e.g., from 75% to 60% over 3 months). 2) Average fill time increasing (gaps taking longer to fill). 3) False breakout rate increasing (gaps starting to fill then reversing). 4) Strategy drawdown exceeding historical norms. 5) Market structure changes (new trading hours, product changes). Response: reduce position sizes, tighten criteria (only highest-probability setups), investigate cause. Edge decay can be temporary (market phase) or permanent (structural change). Adapt or pause until conditions improve.